The present application is divisional of U.S. patent application Ser. No. 10/443,211 filed 22 May 2003 now U.S. Pat. No. 6,961,645, which claims priority to U.S. Provisional Patent Application Ser. No. 60/389,583, filed 18 Jun. 2002.
The present invention relates to an inflatable restraint system, and more particularly to an algorithm which limits the number of satellite sensors which may be active at one time.
Driver side or passenger side supplemental inflatable restraint (SIR) systems typically include an air bag stored in a housing module within the interior of the vehicle in close proximity to the driver and one or more passengers. SIR systems are designed to actuate upon sudden deceleration so as to rapidly deploy an air bag to restrain the movement of the occupants.
More recently, SIR systems are being extended to protect occupants in all rows of the vehicle. Protection of these occupants is accomplished by equipping the vehicle with multiple rows of side impact event satellite sensors which have the ability to provide data and lead the deployment of airbags or other passive safety restraints.
The side impact event satellite sensors may either be a “decision maker” or a “data sender”. “Decision maker” satellites are more expensive because they require a microprocessor to run an algorithm. “Data sending” satellites are preferred from a cost perspective because they do not require a microprocessor. The data sending satellites communicate raw data to a central controller, which contains a microprocessor for executing the algorithm.
The central controller is responsible for running all the necessary impact event algorithms. This may include algorithms for front/rear impact events, algorithms for rollover events, and algorithms for side impact events. The controller must have enough throughput to execute all of these algorithms while still providing normal diagnostic functions. Therefore, the required runtime for each algorithm must be kept as low as possible.
Each row of side impact event protection usually requires two impact event satellite sensors in order to deliver a desired level of performance. One satellite is for the driver side and one is for the passenger side. Each satellite has the ability to wake up an algorithm in the central controller. Therefore, a car with two rows of side protection would have four satellites that may try to run four side algorithms simultaneously.
Disadvantageously, running numerous algorithms could lead to microprocessor runtime issues. The task may be further complicated due to the aggressive deploy times required for side impact events.
Accordingly, it is desirable to provide a wake up and reset strategy, which minimizes the runtime required by the satellite sensor algorithms.